Preheat oven to 170 °Celsius.
Heat up the milk. Cut open one tea bag and place the tea leaves in the milk. Let the tea steep in the hot milk for 3 minutes. Strain and set the tea infused milk aside.
Cut open the remaining 2 tea bags and add the tea into a blender. Add half of the sugar into the blender and process the tea into fine powder.
Transfer the tea and sugar powder into a mixing bowl. Add the remaining sugar and butter.
Beat butter and sugar till light and fluffy for about 2 minutes. Add eggs, one at a time, beating well after each addition.
In a separate bowl, sift flour, baking powder, and salt. Fold in the sifted ingredients into the creamed mixture alternately with the milk tea. Start and end with flour.
Pour the cake batter into a well-greased and floured loaf cake tin. Level the top.
Bake the Earl Grey pound cake for 40 to 45 minutes until a skewer inserted in the center of the cake comes out without any wet batter.
Remove the cake from the oven and let it cool in the tin for 2 minutes before turning it out onto a wire rack to cool further.
To make the lemon curd glaze, measure sugar into a heat proof bowl.
Zest and juice the lemon and add both the zest and the lemon juice into the sugar.
Double boil until the sugar is all melted.
Beat the egg separately and add into the lemon-sugar mixture. Stir constantly to avoid the egg from curdling.
Add butter and continue to stir until the mixture thickens. To test if the curd is done, check the back of the mixing spoon. If you see the curd covering the back of the spoon, it is ready.
Remove the curd from heat. Cover the top with a plastic wrap (make sure the wrap touches the surface of the curd to avoid skin from forming while cooling down).
Once it has cooled down, transfer the curd into a piping bag.
Snip a little hole in the piping bags and drizzle the curd onto the cake.